There is a distinct decline in the level of civility on all the sites here. Some of this is due to new users coming in and posting spam and other nonsense, but the offtopic and downvote buttons are doing a pretty good job of keeping this under control.
Unfortunately, a lot of this is coming from more experienced users, and the site's built-in moderation system is not (and probably cannot) handle this very well. Folks are rushing to pound new users down with "this belongs on meta!", "this is off topic", "this is a duplicate!" and "read the FAQ!". (Which is correct, but should be done nicer) All this, of course, is accompanied by a flurry of downvotes. This is not very welcoming to new users who don't know about meta, or what is offtopic, or the FAQ.
Now I am not proposing that we just allow offtopic, meta, or duplicate questions. However, I think we could be gentler in the way we express these sorts of things. Explain what meta and the FAQ are and provide useful links. Just using please and thank-you when asking folks to read the FAQ or post something on meta would be an improvement. I also think we could rein in the downvoting a bit. Not that we shouldn't vote stuff down, but unless a new user's post is clearly spam, voting it down to -1 or -2 should be sufficient to send a message without piling on.
I like Stack Overflow and I want it to become a resource for everyone, not just an elitist site for people who were in the private beta.